Last Updated on December 11, 2023 by Ankit Kochar
Software testing is a critical aspect of software development, ensuring the reliability, functionality, and security of applications. Two primary methodologies employed in software testing are Blackbox and Whitebox testing. These methodologies approach testing from distinct perspectives, each with its own set of techniques and objectives.Testing is considered to be two types In Black box testing (or "behavioral testing"), the tester understands what the program is supposed to do, rather than its internal working. Whereas, in White box testing, there is the testing of internal coding and infrastructure of software.
What is the Black Box?
Black box testing is the process of analyzing a computer system or other electronic system to ascertain how it functions while being blind to the inner workings of the product. By disassembling sophisticated things like airplanes or medical equipment, a black box testing tester can find security flaws.
Example of Black Box
User-friendly login screens for software or web applications is examined. A username and password are required inputs on the login screen, and the output is used to provide system access. Black box testing disregards code specifications and verifies that the username and password used to log into the right account are legitimate. The inputs and outputs are verified using this testing methodology. The current username and the right password are entered by a registered user. If the user enters the wrong username and password, the error message is shown.
Application of Black Box
An accident could occur if a system on an airplane fails and it crashes. So that accidents don’t happen again, officials will examine the operation of every component of the aircraft to see if it is operating properly and what might have caused the crash.
What is White Box Testing?
The term "white box testing" describes testing an electrical device or computer without opening it up. Without knowing the inner workings of the product, white box testing is conducted on hardware or software. White box testing involves doing routine checks on programs or objects to make sure they work as intended.
White box testing is thorough in contrast to black box testing, which emphasizes creating a seamless user experience. When combined with other bug-slaying techniques, it is a potent quality assurance tool. The goal of this methodology is to thoroughly simulate every scenario that the program might encounter at the code level.
The granularity of white box testing makes it an effective tool for stomping out issues. This open and thorough testing methodology provides information on all potential outputs the application might theoretically produce. White box testing is used to uncover hidden internal bugs and to make code better.
Black box testing methods are frequently used by QA teams to examine every component of an application. Yet, only the most essential components of an application are often subjected to white box testing. This is due to the high resource requirements of white-box approaches. It is employed for tasks that cannot afford to fail, such as national security and payment remittance because they have the power to significantly change living conditions.
What is done in White Box Testing?
- While creating and implementing functions, conditions, or controls outside of your program, logic errors frequently find their way into your work.
- Design flaws resulting from inconsistencies between the intended implementation and the program logic flow
- Syntax and Typo check
Example of White Box Testing
The effects of particular inputs or results on user experience or functioning are the subject of test engineers’ hypotheses.
For example:
- Will the server’s CPU utilization rise if I alter this value in the program code?
- Would the performance of this system suffer if I unplug this component?
- When a user is sat in this position, which keyboard goes with which monitor?
- When printing on this kind of paper, which plotter goes with this printer?
Application of White Box Testing
White box testing is done-
- Any website that is attacked will have its code altered to manage additional user traffic.
- When a website’s buttons or options don’t function.
- Each website under assault will have its source code examined to look for security holes.
Key Points about Black Box and White Box Testing
- White-box testing is carried out with the knowledge of the internal structure of the program, whereas black-box testing is carried out without understanding the program’s structure or application.
- Whereas white box testing necessitates programming knowledge, black box testing does not.
- White-box testing concentrates on the code structure, conditions, pathways, and branching while black-box testing concentrates on the external or end-user perspective.
- White box testing offers more granular reporting than black box testing, which offers less granular information.
- Black box testing is a quick process, whereas white box testing takes time, as compared to the other types of testing.
Black Box Testing Vs. White Box Testing
Below is the main difference between White Box and Black Box Testing:
| Parameter | Black Box testing | White Box testing |
|---|---|---|
| Basic | It is a method of software testing that looks at a program’s functionality without knowing anything about its coding or internal structure. | The internal architecture of the software is known to the tester during white-box testing. |
| Alias | Functional testing, data-driven testing, and closed-box testing are other names for black box testing. | It is also referred to as transparent testing, code-based testing, structural testing, and clear box testing. |
| Programming Knowledge | Black-box testing necessitates less programming expertise. | Programming skills are necessary for white-box testing. |
| Algorithm testing | Testing algorithms is not a good use for it. | It is a good fit and is advised for testing algorithms. |
| Usage | Higher levels of testing, such as system testing and acceptability testing, are where it is carried out. | Unit testing and integration testing are the lower layers of testing where it is carried out. |
| Implementation knowledge | No Implementation knowledge is required for BlackBox testing. | There is a requirement for implementation knowledge in WhiteBox testing. |
| Automation | Black-box testing is difficult to automate since programmers and testers rely on one another. | Automating white box testing is simple. |
| Objective | The main aim of implementing black box testing is to specify the business needs or the customer’s requirements. | Its main aim is to check the code quality. |
| The base for test cases | The base of this testing is external expectations. | The base of this testing is coding which is responsible for internal work. |
| Tested by | Performed by software testers. | Performed by software developers. |
| Granularity | is low as compared to white box testing. | Granularity is high as compared to black box testing. |
| Testing method | It is based on a trial and error method. | Data domain and internal boundaries can be tested. |
| Time | It is less exhaustive and time-consuming as compared to white box testing. | The exhaustive and time-consuming method as compared to black box testing. |
| Algorithm test | is Not the best method for algorithm testing. | Best suited for algorithm testing. |
| Code Access | For Black Box Testing, code access is not required. | White box testing requires code access. Thereby, the code can be stolen if testing is outsourced. |
| Exhaustive | Compared to White Box testing, it is less exhaustive. | In comparison to Black Box testing, it is more thorough. |
| Defect detection | Once the code is ready, problems are found via black-box testing. | However, there is a chance of early defect detection using white box testing. |
| Types | Functional testing, Non-Functional testing, and Regression testing are the three main categories of black-box testing. | Path, Loop, and Condition testing are three types of white box testing. |
| Errors | The errors in the code are not discovered. | White-box testing allows for the finding of concealed mistakes. The code’s optimization also helps. |
Conclusion
Both Blackbox and Whitebox testing methodologies play indispensable roles in ensuring software quality. While Blackbox testing assesses functionality and behavior from a user’s viewpoint, Whitebox testing scrutinizes the internal workings of the software. The combination of these testing approaches helps in achieving comprehensive test coverage, thereby enhancing the reliability and quality of software applications.
FAQ Related to Blackbox and Whitebox Testing
Here are some FAQs related to BlackBox and WhiteBox testing.
Q1: Which testing methodology is more suitable for finding logical errors in code?
A: Whitebox testing is better suited for uncovering logical errors within the code as it allows testers to scrutinize the internal logic, paths, and conditions of the software.
Q2: Can the same test cases be used for both Blackbox and Whitebox testing?
A: Test cases for Blackbox and Whitebox testing differ significantly as Blackbox focuses on functional aspects and user requirements, while Whitebox examines internal structures and code paths. While some test cases might overlap, they are generally distinct due to the different testing objectives.
Q3: Are there any limitations to using Blackbox or Whitebox testing exclusively?
A: Yes, both methodologies have limitations. Relying solely on Blackbox testing might overlook certain internal issues, while Whitebox testing might miss user experience or behavioral discrepancies. Combining both methodologies, known as Greybox testing, can offer more comprehensive coverage.
Q4: How do these testing methodologies impact software development timelines?
A: Both Blackbox and Whitebox testing are crucial stages in software development. While they may extend development timelines, their implementation ensures higher software quality, reducing the probability of post-release issues and enhancing user satisfaction.